Many gesture recognition systems typically employ complex and complicated time of flight cameras, stereo cameras, or other such sophisticated systems. In order to determine action in a z-axis direction relative to a camera, time of flight cameras are equipped with a system for determining a distance from the camera at any time. Similarly, a stereo camera system is able to employ a triangulation or other stereo distance determination. Each of these systems is a complex system not typically employed in a standard computer laptop or other mobile device. Therefore, these systems are not available for use in a more typical computer or mobile device environment.
In order to overcome these drawbacks, various systems employ complex hybrid systems to overcome the z-axis. For example, U.S. Pat. No. 7,774,075 presents a method and apparatus for determining an object's three-dimensional location (i.e. real world coordinates) using the audio-video infrastructure of a 3G cellular phone or a 3C (Computer, Communications, Consumer) electronic device. A first detection device (e.g. a camera) is used to capture images of the objects. The captured image data is used to compute location data of the object in a first two-dimensional plane. A second detection device (e.g. microphone or infrared detector) may be used to collect additional location data in a second plane, which when combined with image data from the captured images allows the determination of the real world coordinates (x, y, z) of the object. The real-world coordinate data may be used in various applications.
In an alternative embodiment of this '075 patent, if the size of an object of interest is known or can be calculated, and the size of the projected image does not vary due to rotation of the object, a single camera (e.g. the camera in a 3G or 3C mobile device) may be used to obtain three-dimensional coordinate data for the applications.
For use in mobile or other unstable environments, however, calculation of a precise 3D coordinate may be difficult because of various factors. Furthermore, there is no way to guarantee that the object will not rotate. Furthermore, a mobile or other portable platform may result in a webcam that is likely to be moved about quite a bit, thus potentially requiring frequent recalibration of the system. Furthermore, movement may be improperly interpreted as deliberate action, thus resulting in false actions being taken by the system. Therefore, it would be beneficial to provide a method and apparatus that overcome the drawbacks of the prior art.